Pump



June 11, 1963 G. DERDERIAN 3,093,084

PUMP

Filed Feb. 21, 1961 INVENTOR.

B? WW 3,093,084 Patented June 11, 1963 P MP George Derderian, 239 W. 8th St., Erie, Pa. Filed Feb. 21, 1961, Ser. No. 90,717 7 Claims. (Cl. 10387) This invention is a centrifugal pump or compressor in which the blades are carried by a rotary housing surrounding a stationary difiuser section between the blades and the fluid outlet. It wfll pump any fluid, liquid or gas. Compactness is achieved by having the diffuser section extend radially inward from the tips of the blades. Other advantages are reduction in disc friction losses between the fluid and stationary parts of the pump, elimination of seals and reduction in slip between the fluid and the impeller blades. Two pumps may be mounted on opposite sides of a turbine rotor and used as a two propellant turbo pump system for rocket engines.

In the drawing, 'FIG. 1 is a longitudinal section through a preferred form of turbo pump and FIG. 2 is a section on line 22 of FIG. 1 through one of the turbine buckets.

The fluid to be compressed enters through an inlet 1 and is discharged through an outlet2, the discharge being taken from an annular discharge structure 3 surrounding the inlet structure 4. The inlet and outlet form the part of a stationary structure supported by mounting flanges 5 and 6.

The inlet leads to impeller blades 7 carried by a rotatable housing 8 having axially spaced end walls 8a, 8b and a connecting peripheral wall 80. The blades 7 are fixed to the end wall 8a with the inner ends adjacent the center of the housing and the outer ends adjacent the peripheral wall of the housing. The edges of the blade 7 remote from the wall 8a may be connected by a shroud 9 having a running clearance with a wall 10 of a toroidal section 11 fixed to the inlet structure 4. The parts 9 and 10 pro vide a labyrinth seal which prevents or minimizes leakage. The housing is rotated by a turbine wheel 12 fixed to Wall 8a. The driving fluid for the turbine is supplied through an annular chamber 13 having nozzles 14 directed toward the turbine buckets "15'. The fluidbeing pumped is in contact with the hub of the turbine wheel and acts as a coolant. This is a significant advantage in gas turbines. The turbine buckets are anchored in the turbine wheel by axially extending dovetails 15a as shown in FIG. 2. Axial displacement of the blades is prevented by the shoulders 8d on the housing. This is particularly advantageous when there is a compressor on each side of the turbine whel as contemplated in FIG. 1, as this eliminates the use of bucket locking tabs.

In passing through the blades 7, the fluid rotates at the same speed as the housing so that upon being discharged fro-m the outer ends or tips 16 of the blades the fluid has a very considerable increase in energy. Part of the in crease in energy is due to centrifugal force but ordinarily the greater part of the increase in energy will be the rotational energy of the fluid about the axis of the pump. In the region between the tips 16 of the blades 7 and the diffuser vanes 17, the fluid is rotating at high velocity but since the casing is rotating at the same speed as the fluid, slip is minimized. Since there is negligible slip, the rotational energy of the fluid is recaptured by diffuser vanes '17 carried by wall 18 of the toroidal section. The outer tips 19 of the diffuser vanes 17 are presented to the discharge tips 16 of the blades 7 and are inclined in the usual manner so as to convert the rotational velocity of the fluid into static pressure. The inner ends of the vanes discharge to the annular pasageway 3 leading to the outlet 2.

There is some opportunity for leakage of liquid between the wall 8b of the rotating housing and the wall 22 attached to the diffuser vanes 17. This leakage is prevented by blades 23 attached to the inner surface of the wall 8b of the housing and difluser vanes 24 attached to the outer surface of the wall 22. The combined effect of the blades 23 and difluser vanes 24 is to return any fluid to the region between the tips 16 and 19 of the blades and difluser vanes.

A seal 25 is provided between the wall'22 and the rotating housing but this seal is not necessary unless the fluid being pumped is a gas. The seal protects the bearing 26 on which the rotary housing may be journaled.

The pump has high capacity in a small space, first because the diffuser acts throughout the entire circumference of the rotary housing and second because the diffuser extends from the outer part back toward the axis of the rotary housing.

The pump is adapted to high speeds because the fluid is uniformly distributed about the axis of rotation.

From one aspect, the blades 23 and diffuser vanes 24 constitute a centrifugal pump which produces a pressure sufficient to more than balance the pressure created by vanes 7 and thus prevent any leakage. Thus a controlled fluid level is maintained in the region between the walls 8b and 22.

When a pump is mounted on each side of the turbine wheel, each pump may handle a difierent fluid, e.g. pump on both sides of the turbine for two propellant turbo pump system used in rocket engines; pump on one side and an air compressor on the other side, discharge air from compressor may be burned and expanded through turbine to provide power for both compressor and'pump or other auxiliary equipment other than pump; compressor on both sides of turbine. This arrangement may be used for turbocharger or turbojet engine. In a turbocharger, the ex{ haust gases from an internal combustion engine drive the turbine which in turn'drives the compressor to compress air to the engine whereas in a turbojet, the discharge gases from the compressor are burned and passed through the turbine and used for thrust. I v

The compressor will run as a turbine, in which case the driving fluid is supplied through the outlet 2 and dis-' charges through the inlet 1. This is the reverse of the fluid flow when operated as a compressor.

What is claimed as new is:

1. A pump comprising a rotatable housing having axially spaced end walls facing each other and a connect ing peripheral wall, impeller blades fixed to one of the end walls with inner ends adjacent the center of the housing and outer ends or discharge tips adjacent said peripheral wall of the housing, a stationary central inlet structure conducting fluid to the inner ends of the blades, a stationary difl'user section having a shroud adjacent the other of the end walls and angularly spaced diffuser vanes adjacent said central inlet structure and extending from adjacent said peripheral wall back toward the center of the housing, the outer tips of the diffuser vanes being presented to the discharge tips of the blades, a stationary outlet structure conducting fluid from the center of the diffuser section, other blades fixed on said other end wall for returning toward said peripheral wall fluid which may leak between said other end wall and the adjacent shroud of the diffuser section, and means for rotating the housing.

2. A pump comprising a rotatable housing having axially spaced end walls facing each other and a connecting peripheral wall, a stationary structure including a part between said end walls, impeller blades between one side of said part and one of the end walls, said blades being fixed to said one of the end walls with inner ends adjacent the center of the housing and outer ends or discharge tips adjacent said peripheral wall of the housing, diffuser vanes between the other side of said part and the other of said end walls, said diffuser vanes being fixed to said part and extending from adjacent said peripheral wall back toward the center of the housing, the outer tips of the diffuser vanes being presented to the discharge tips of the blades, said blades and vanes being distributed about the axis of the pump, a shroud on said vanes having a running clearance with said other end wall, other impeller blades fixed on said other end wall for preventing leakage between said other end wall and the shroud of the diffuser vanes, and an inlet and an outlet in said stationary structure.

3. A pump comprising a rotatable housing, means for rotating the housing, said housing having axially spaced end walls facing each other and a connecting peripheral wall, one of the end walls being closed and the other end wall having a central opening, a stationary structure extending through said central opening and having a part disposed between said end walls, impeller blades disposed on one side of said part and diffuser vanes disposed on the opposite side of said part, said blades being fixed to one of the end walls with inner ends adjacent the center of the housing and outer ends or discharge tips adjacent said peripheral wall of the housing, said vanes being fixed to said part and extending from adjacent said peripheral well back toward the center of the housing, the outer tips of the diffuser vanes being presented to the discharge tips of the blades, said blades and vanes being distributed about the axis of the pump, a shroud on said vanes having a running clearance with said other end Wall, other impeller blades fixed on said other end wall for preventing leakage between said other end wall and the shroud wall of the diffuser vanes, and an inlet and an outlet in said stationary structure.

4. A turbo pump comprising a turbine wheel having buckets on its periphery, a rotatable pump housing having axially spaced end walls facing each other and a connecting peripheral wall, one of the end walls being fixed to one side of said turbine wheel, a stationary structure including a part between said end walls, impeller blades between one side of said part and said one of the end walls, said blades being fixed to said one of the end walls with inner ends adjacent the center of the housing and outer ends or discharge tips adjacent-said peripheral wall of the housing, diffuser vanes between the other side of said part and the other of said end walls, said diffuser vanes being fixed to said part and extending from adjacent said peripheral wall back toward the center of the housing, the outer tips of the diffuser vanes being presented to the discharge tips of the blades, said blades and vanes being distributed about the axis of the pump.

5. The pump of claim 4 in which a similar pump is fixed to the opposite side of the turbine wheel.

6. A turbo pump comprising a turbine wheel having buckets on its periphery, the buckets and Wheel having axially facing dovetail connections, a rotatable pump housing having axially spaced end walls facing each other and a connecting peripheral wall, said housing being opposite said dovetail connections and blocking removal of the buckets from the Wheel, one of the housing end walls being fixed to said wheel, a stationary structure including a part between said end walls, impeller blades between one side of said part and said one of the end walls, said blades being fixed to said one of the end Walls with inner ends adjacent the center of the housing and outer ends or discharge tips adjacent said peripheral wall of the housing, diffuser vanes between the other side of said part and the other of said end walls, the outer tips of the diffuser vanes being presented to the discharge tips of the blades, said diffuser vanes being fixed to said part and extending from adjacent said peripheral wall back toward the center of the housing, said blades and vanes being distributed about the axis of the pump.

7. A pump comprising a rotatable housing having axially spaced end walls facing each other and a connecting peripheral wall, first impeller blades fixed to one of the endwalls with inner ends adjacent the center of the housing and with outer ends or discharge tips presented toward the peripheral wall of the housing, a stationary central inlet structure conducting fluid to the inner ends of the first blades, a stationary diffuser section having fixed angularly spaced diffuser vanes extending from adjacent said peripheral wall back toward the center of the housing, the outer tips of the diffuser vanes being presented toward the discharge tips of the first blades, a stationary outlet structure conducting fluid from the center of the diffuser section, second impeller blades fixed to the other of said end Walls and discharging toward the peripheral wall, second diffuser vanes fixed on said diffuser section and receiving the discharge of said second impeller blades and conducting the same toward the fluid discharged from said first impeller blades, and means for rotating the housmg.

References Cited in the file of this patent UNITED STATES PATENTS 220,108 Babbitt Sept. 30, 1879 1,719,415 Back July 2, 1929 2,673,075 Borck Mar. 23, 1954 FOREIGN PATENTS 88,945 Switzerland Aug. 16, 1921 737,933 Great Britain Oct. 5, 1955 

1. A PUMP COMPRISING A ROTATABLE HOUSING HAVING AXIALLY SPACED END WALLS FACING EACH OTHER AND A CONNECTING PERIPHERAL WALL, IMPELLER BLADES FIXED TO ONE OF THE END WALLS WITH INNER ENDS ADJACENT THE CENTER OF THE HOUSING AND OUTER ENDS OR DISCHARGE TIPS ADJACENT SAID PERIPHERAL WALL OF THE HOUSING, A STATIONARY CENTRAL INLET STRUCTURE CONDUCTING FLUID TO THE INNER ENDS OF THE BLADES, A STATIONARY DIFFUSER SECTION HAVING A SHROUD ADJACENT THE OTHER OF THE END WALLS AND ANGULARLY SPACED DIFFUSER VANES ADJACENT SAID CENTRAL INLET STRUCTURE AND EXTENDING FROM ADJACENT SAID PERIPHERAL WALL BACK TOWARD THE CENTER OF THE HOUSING, THE OUTER TIPS OF THE DIFFUSER VANES BEING PRESENTED TO THE DISCHARGE TIPS OF THE BLADES, A STATIONARY OUTLET STRUCTURE CONDUCTING FLUID FROM THE CENTER OF THE DIFFUSER SECTION, OTHER BLADES FIXED ON SAID OTHER END WALL FOR RETURNING TOWARD SAID PERIPHERAL WALL FLUID WHICH MAY LEAK BETWEEN SAID OTHER END WALL AND THE ADJACENT SHROUD OF THE DIFFUSER SECTION, AND MEANS FOR ROTATING THE HOUSING. 